/**
 * loading 占位
 * 解决首次加载时白屏的问题
 */
(function () {
  const _root = document.querySelector('#app');
  if (_root && _root.innerHTML === '') {
    _root.innerHTML = `
        <style>
          html,
          body,
          #root {
            height: 100%;
            margin: 0;
            padding: 0;
          }
          #root {
            background-repeat: no-repeat;
            background-size: 100% auto;
          }
  
          .loading-title {
            font-size: 1.1rem;
          }
  
          .loading-sub-title {
            margin-top: 20px;
            font-size: 1rem;
            color: #888;
          }
  
          .page-loading-warp {
            display: flex;
            align-items: center;
            justify-content: center;
            padding: 26px;
          }
          .ant-spin {
            position: absolute;
            display: none;
            -webkit-box-sizing: border-box;
            box-sizing: border-box;
            margin: 0;
            padding: 0;
            color: rgba(0, 0, 0, 0.65);
            color: #1890ff;
            font-size: 14px;
            font-variant: tabular-nums;
            line-height: 1.5;
            text-align: center;
            list-style: none;
            opacity: 0;
            -webkit-transition: -webkit-transform 0.3s
              cubic-bezier(0.78, 0.14, 0.15, 0.86);
            transition: -webkit-transform 0.3s
              cubic-bezier(0.78, 0.14, 0.15, 0.86);
            transition: transform 0.3s cubic-bezier(0.78, 0.14, 0.15, 0.86);
            transition: transform 0.3s cubic-bezier(0.78, 0.14, 0.15, 0.86),
              -webkit-transform 0.3s cubic-bezier(0.78, 0.14, 0.15, 0.86);
            -webkit-font-feature-settings: "tnum";
            font-feature-settings: "tnum";
          }
  
          .ant-spin-spinning {
            position: static;
            display: inline-block;
            opacity: 1;
          }
  
          .ant-spin-dot {
            position: relative;
            display: inline-block;
            width: 20px;
            height: 20px;
            font-size: 20px;
          }
  
          .ant-spin-dot-item {
            position: absolute;
            display: block;
            width: 9px;
            height: 9px;
            background-color: #1890ff;
            border-radius: 100%;
            -webkit-transform: scale(0.75);
            -ms-transform: scale(0.75);
            transform: scale(0.75);
            -webkit-transform-origin: 50% 50%;
            -ms-transform-origin: 50% 50%;
            transform-origin: 50% 50%;
            opacity: 0.3;
            -webkit-animation: antspinmove 1s infinite linear alternate;
            animation: antSpinMove 1s infinite linear alternate;
          }
  
          .ant-spin-dot-item:nth-child(1) {
            top: 0;
            left: 0;
          }
  
          .ant-spin-dot-item:nth-child(2) {
            top: 0;
            right: 0;
            -webkit-animation-delay: 0.4s;
            animation-delay: 0.4s;
          }
  
          .ant-spin-dot-item:nth-child(3) {
            right: 0;
            bottom: 0;
            -webkit-animation-delay: 0.8s;
            animation-delay: 0.8s;
          }
  
          .ant-spin-dot-item:nth-child(4) {
            bottom: 0;
            left: 0;
            -webkit-animation-delay: 1.2s;
            animation-delay: 1.2s;
          }
  
          .ant-spin-dot-spin {
            -webkit-transform: rotate(45deg);
            -ms-transform: rotate(45deg);
            transform: rotate(45deg);
            -webkit-animation: antrotate 1.2s infinite linear;
            animation: antRotate 1.2s infinite linear;
          }
  
          .ant-spin-lg .ant-spin-dot {
            width: 32px;
            height: 32px;
            font-size: 32px;
          }
  
          .ant-spin-lg .ant-spin-dot i {
            width: 14px;
            height: 14px;
          }
  
          @media all and (-ms-high-contrast: none), (-ms-high-contrast: active) {
            .ant-spin-blur {
              background: #fff;
              opacity: 0.5;
            }
          }
  
          @-webkit-keyframes antSpinMove {
            to {
              opacity: 1;
            }
          }
  
          @keyframes antSpinMove {
            to {
              opacity: 1;
            }
          }
  
          @-webkit-keyframes antRotate {
            to {
              -webkit-transform: rotate(405deg);
              transform: rotate(405deg);
            }
          }
  
          @keyframes antRotate {
            to {
              -webkit-transform: rotate(405deg);
              transform: rotate(405deg);
            }
          }
        </style>
  
        <div style="
          display: flex;
          flex-direction: column;
          align-items: center;
          justify-content: center;
          height: 100%;
          min-height: 362px;
        ">
          <div class="page-loading-warp">
            <div class="ant-spin ant-spin-lg ant-spin-spinning">
              <span class="ant-spin-dot ant-spin-dot-spin">
                <i class="ant-spin-dot-item"></i>
                <i class="ant-spin-dot-item"></i>
                <i class="ant-spin-dot-item"></i>
                <i class="ant-spin-dot-item"></i>
              </span>
            </div>
          </div>
          <div class="loading-title">
            正在加载资源
          </div>
          <div class="loading-sub-title">
            初次加载资源可能需要较多时间 请耐心等待
          </div>
        </div>
      `;
  }
})();